Maybe someone should do a cost-benefit analysis here. The reason the RWNJs are against illegals is they allegedly are using social services. There is little to no proof of this of course. The other argument is that they are "taking our jobs." I'm not a numbers cruncher but common sense tells us that the $25B spent on this project is going to far surpass any amount that they are supposedly taking out of the system.
According to this source, Asians comprise a surprisingly large number of illegals. Hmmm, build a wall around the entire country? Won't that mess up Trump's beachfront property views?
http://www.pewresearch.org/fact-tank/2017/04/27/5-facts-about-illegal-immigration-in-the-u-s/